A method and equipment for molding an article produced from paperboard or cardboard. Moulding is carried out by a molding tool that mechanically works the board; and to improve its moldability, momentary irradiation on the microwave frequency is exerted on the board. The method applies to the manufacture of packages and disposable containers made of paperboard or cardboard; for example, to the forming of a rolled-up or folded rim around a drinking cup, mug or a container, the forming of a stiffening crease or projection on a paperboard container, or to press molding of paperboard containers or plates.